1. Technical Field
The present invention relates to a technique field of a regenerative brake control device for an electric-powered vehicle, which obtains a regenerative braking force by regenerative-driving an electric motor that is a power source for traveling.
2. Background
There has been known an electric-powered vehicle that travels by driving, as a power source for travelling, an electric motor by using electric power stored in a battery (it is noted that the electric-powered vehicle in the present application is considered as a concept that includes electric vehicles having an electric motor as a power source for travelling and hybrid electric vehicles having an internal combustion engine, in addition to the electric motor). In these types of electric-powered vehicles, a braking force (regenerative braking force) is obtained by regenerative-driving the electric motor during deceleration and the kinetic energy of the vehicle is collected as the electric energy by regenerative power generation. From the viewpoint of energy efficiency, it is desirable to obtain more regenerative power generation amount by setting the regenerative braking force to be high. However, in this case, the deceleration is increased and therefore adverse effect on the drivability may increase. For this reason, it is necessary to set the regenerative braking force during deceleration in consideration of the energy efficiency or the drivability.
In view of such circumstances, Japanese Utility-Model Registration No. 2579650 discloses a technique that a driver can select, step by step, the magnitude of regenerative braking force (regeneration level) during deceleration by operating an operation member such as a shift lever. With this configuration, it is possible to obtain actively the regenerative braking force that the driver considers necessary in accordance with the travelling state. Accordingly, it is possible to achieve both the energy efficiency and the drivability.
In Japanese Utility-Model Registration No. 2579650, the regenerative braking force (regeneration level) is controlled stepwise according to the number of operations of the operation member. Here, the regenerative braking force that is intended by a driver during actual travelling is different and therefore such an operation member needs operability according to the travelling state. When it is intended to reduce the operation load of a driver (for example, as in the case of the city driving), it is preferable that the regenerative braking force can be changed to a predetermined regeneration level with a small number of operations. On the contrary, when it is intended to delicately control the switching of the regenerative braking force (for example, as in the case of the sport driving), it is preferable that the regenerative braking force can be changed to a predetermined regeneration level with a large number of operations.
However, in Japanese Utility-Model Registration No. 2579650, the number of operations of the operating member required to change the regenerative braking force to a predetermined regeneration level is uniquely determined in advance and therefore a driver cannot change the number of operations. Accordingly, it is difficult to cope with such various demands.
The present invention has been made to solve the above-described disadvantages and an object thereof is to provide a regenerative brake control device that is capable of easily controlling a regenerative brake to a predetermined regeneration level with operability according to the travelling state.